Spring Boot Hello World Example Not working

Question

I have downloaded spring boot example from https://start.spring.io/.

I tried many times but i get same error again and again:

Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/boot/SpringApplication
    at com.example.demo.Application.main(Application.java:10)
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication

Here is my pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>SpringBoot</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>SpringBoot</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

and SpringBootClass

package com.example.demo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

also my ControllerClass

package com.example.demo.controller;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
@EnableAutoConfiguration
public class HelloWorldController {

@RequestMapping("/hello")
@ResponseBody
public String sayHello() {
return "Hello World Developer!!!";
}
}

I am struggling from past three days and not getting any help from anywhere. I am using Spring Tool Suite I am new to Spring Boot and need help here

I simply run the app as SpringBoootApp in STS or i click the green icon in main class — AnkushSeth, Jan 09 '20 at 06:20

score 0 · Answer 1 · answered Jan 08 '20 at 15:50

Set Maven to you path and try from command prompt/ terminal with command: mvn clean install this will create jar file in target folder. go to target folder and run java -jar jarName.jar.

OR

Try cleaning the project from project tab, Add all the maven dependencies to eclipse build path. Then try running it as java application.

Alien · Answer 2 · 2020-01-09T08:10:57.637

0

It is caused by a corrupt Maven repository.

Delete everything under C:\Users\<me>\.m2\repository.

Then do Eclipse Maven Update, and it will work.

it is like spring-boot.jar got corrupted.

edited Jan 09 '20 at 08:10

answered Jan 09 '20 at 06:59

Alien

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Spring Boot Hello World Example Not working

2 Answers2